1. Field of the Invention
The present invention relates to an optical device, especially to an optical assembly position adjustment device.
2. Description of Related Art
In recent years, as the demand for data throughput and transmission speed goes up, the traditional way using copper cables as the medium of data transmission is gradually out of date; therefore fiber transmission has taken the place of copper transmission to be the major means for high speed transmission, particularly long-distance transmission.
As the development of technology, the transmission speed of a commercial optical transceiver has reached hundreds of GHz (gigabit/s). Such high speed optical transceiver should be made with great precision of assembly position and focus alignment. In consideration of a device part is usually built to a certain tolerance, a fine tune process is often required; therefore, techniques to adjust assembly position and focus are required. However, in current arts, both active alignment techniques and passive alignment techniques are hard to precisely adjust assembly position and focus in a cost-effective way. As a result, this industrial field should choose to improve optical coupling efficiency with the increase of assembly cost, or choose to sacrifice optical coupling efficiency for the reduction of cost.
Besides, the current active alignment techniques have many disadvantages such as taking a lot of time to adjust an optical axis, requiring numerous and complicated optical assemblies, low design tolerance, and being vulnerable to heat, shake, deterioration of adhesive, and shock. In order to solve these disadvantages, production cost may greatly increase. On the other hand, a passive alignment technique is better for the control of cost, and a better passive alignment technique is found in Applicant's U.S. patent application “OPTICAL SUB-ASSEMBLY AND PACKAGING METHOD THEREOF” (application Ser. No. 14/076,996).